Non-gelling bituminous composition and a method of preparing it



NON-GELLING BITUNIINOUS COMPOSITION AND A METHOD OF PREPARING IT LewisA. Winkler, Scotch Plains, and Walter E. Waddey,

Roselle, N. .L, assiguors to Esso Research and Engineering Company, acorporation of Delaware No Drawing. Application July 17, 1951,

I Serial No. 237,278

3 Claims. (Cl. 106-123) This invention relates to improved protectivecoating compositions for metal surfaces and more particularly relates toan improved asphalt composition for such purposes.

Specialty cutback asphalts are finding increasing use as protectivecoatings, particularly as the base material in the manufacture ofautomobile undercoating compounds. Such coatings are made from oxidizedasphalt which have 'the great disadvantage that they tend to gel orthicken excessively during storage, leading to application difliculties.

One object of the present invention is the preparation of an oxidizedasphalt composition which remains fluid .during storage.

Another object of this invention is to prepare an oxidized :asphaltcomposition which has improved properties when used as a rust preventingcoating for metals.

These and other objects of this invention are attained 'by the additionto an oxidized asphalt of a mixture of primary aliphatic amines and afatty acid.

The oxidized asphalt used in this invention may be obtained by anymethod known to the art, such as by bub- Lbling air or oxygen throughhot asphalt.

Suitable amines include those having 16-18 carbon atoms in the chain,such as hexadecyl amine, heptadecyl amine and octadecyl amine or theirmixtures. Suitable fatty acids include those having 1519 carbon atoms inthe alkyl radical, such as oleic, stearic, palmitic, margaric,

:nondecylic, linoleic and abietic acid or other rosin acids.

The proportion of amines used in the mixture is always larger than thatof the acid. A suitable proportion is 60 parts by weight of amine to 40parts of acid. This mixture is then added to an already gelled oxidizedasphalt in proportions of about 0.5-3% by volume, while refluxing the:asphalt with a naphtha diluent to break down the gel :structure. thegel structure from reforming.

The presence of the addition agent prevents The following examplesillustrate the improved results =obtained by the composition of thisinvention.

Example 1 decyl, 25% octadecyl and 45% octadecenyl n-primary amines and40% of highly refined tall oil (approximately 45 oleic acid, 45 linoleicacid, and rosin acids). The additive containing asphalt was then placedin storage along with a material of the same composition not connitedStates Patent 2,764,495 Patented Sept. 25, 1956 taining the additive.Viscosity data obtained on the two samples during storage are asfollows:

, Outback Outback Viscosity (Poises) After Storage For without with0.67%

Additive Additive The additive can also be used to lower the viscosityand inhibit future gelling of cutbacks that have already thickened bysimple addition in the presence of gentle refluxing.

Example 2 Extent of Busting Observed on Test Panel 1 Rust PreventiveOomposition, Wt. Percent 20% Salt 4% Salt Spray, Humidity Spray, 10 DaysCabinet, 10 Days 28 Days 1. Outback Asphalt Medium Medium Light. 2. 2.5%of a heavy coastal do Trace-Medium Do.

phenol extract in Outback Asphalt. 3. (2) 1.0% amine-acid- None NoneNone.

mixture.

1 280 grit polished, sandblasted, and highly polished steel panels.

The nature of the present invention having been thus fully set forth andspecific examples of the same given, what is claimed as new and usefuland desired to be secured by Letters Patent is:

1. An improved rust proofing, non-gelling bituminous material whichcomprises an oxidized cutback asphalt containing 0.5 to 0.75% by weightof a mixture of 60% by weight of a mixture of approximately 30% byweight of hexadecyl, 25% octadecyl, and 45% of octadecenyl normalprimary amines and 40% of refined tall oil.

2. A method of breaking down a gelled oxidized asphalt and stabilizingit against regelling which comprises refluxing an already gelledoxidized asphalt with a naphtha 1 The test panels are dipped in the rustpreventive formulation and then removed for a four hour drying period.The coated specimens are then placed on a rack so that the significantsurface is 15 from the vertical and parallel to the principal directionof the horizontal fiow of the fog through the chamber. The salt solutionis atomized by warm humidified air to produce a salt fog of the requiredconcentration at a temperature F. plus 2 or minus 3 F. At the end of thetest period the coating is removed and the surface examined for evidenceof rusting.

2 Test panels are dipped in the rust preventive and then allowed to dryfor four hours. These coated specimens are then suspended on a rotatingrack in the humidity cabinet, using stainless steel or Monel hooks andsubjected to a continuous flow of moisture-saturated air at F. withcontinuous condensation on the test panels. At the end of the testperiod, the panels are removed, the coating dissolved with a suitablesolvent, and examined for evidence of rusting.

and stabilizing it against regelling which comprises refluxing analready gelled oxidized asphalt with a naphtha diluent andsimultaneously adding 0.5 to 3% by Weight of 30% by weight of hexadecyl,25% octadecyl, and 45% of octadecenyl normal primary amines and 40% ofrefined tall oil.

References Cited in the file of this patent a mixture of 60% by Weightof a mixture of approximately 10 2,520,356

UNITED STATES PATENTS Allen Feb. 18, Fischer Feb. 15, Summer Aug. 2,Bishop Aug. 29,

1. AN IMPROVED RUST PROOFING NON-GELLING BITUMINOUS MATERIAL WHICHCOMPRISES AN OXIDIZED CUTBACK ASPHALT CONTAINING 0.5 TO 0.75% BY WEIGHTOF A MIXTURE OF 60% BY WEIGHT OF A MIXTURE OF APPROXIMATELY 30% BYWEIGHT OF HEXADECYL, 25% OCTADECYL, AND 45% OF OCTADECENYL NORMALPRIMARY AMINES AND 40% OF REFINED TALL OIL.